UK National Energy System Operator's grid stability concerns

An 830‑metre underground duct has been completed at Dounreay, linking the electricity grid in Caithness with Orkney, marking a major construction milestone for SSEN Transmission.

The National Energy System Operator (Neso) has repeatedly failed to submit required risk and planning reports to the energy regulator Ofgem, leading to a suspension of its reporting obligation. Neso’s proposal to water down grid stability standards was rejected after a stakeholder consultation, yet the operator successfully applied to reduce the grid’s inertia‑based shock‑absorbing system, arguing that ultra‑fast batteries would provide cheaper backup and save about £96 million annually.

Despite these changes, Neso acknowledges that the likelihood of a severe frequency drop – which could cause power cuts – has risen, with the risk of a major disruption increasing from a one‑in‑27‑year event to a one‑in‑seven‑year event.